In most organisations without one, the requisition already exists: it is an email to a manager asking whether something can be bought. An online requisition system does not add a step, it formalises one that is already happening, and the value is entirely in what the email cannot do, which is show the requester where their request is and leave a record that outlives a mailbox.
What it adds over the email
A status the requester can see without asking. An owner who is definitely the right person rather than probably. An automatic route onward when that person is away. And a record of the decision that lives in the organisation rather than in two mailboxes. None of those are exciting; together they remove most of the chasing that surrounds informal approval.
Keeping the form short
The commonest way to kill a requisition system is to ask for too much on the form. Requesters are not finance people and will avoid a screen that asks fifteen questions. What, roughly how much, which budget, when, and why is usually enough for a decision. Anything else can be added by purchasing after approval.
Making the answer visible
An approved request should tell the requester what happens next and when, and a rejected one should say why. Silence is what drives people to buy things another way. This is a copywriting problem more than a software one, and it is worth spending an hour on the wording of the three notifications the system sends.
Questions people ask about online requisition system
Will people actually use it?
They will if it is faster than the email it replaces and if they can see the status. They will not if it adds a day, whatever the policy says.
Do we need it if managers already approve by email?
You already have the process; the system adds visibility and a durable record. Whether that is worth paying for depends on how much chasing the email version generates.
Should it enforce budgets?
It can show budget position, which helps. Hard enforcement often produces workarounds at the worst moments, so most organisations show rather than block, and review afterwards.